The present invention relates to an engine control system, or more in particular to a system for controlling the engine optimally by a correction factor.
An engine control system is well known in which a correction factor is stored, and control values are corrected in an optimal manner by the correction factor. In this method, the control accuracy is improved by correctly determining the correction factor. In a conventional system, the correction factor is held in a RAM of a digital computer to which a voltage is continuously applied in a manner not to lose the data stored therein. An example of such a conventional system is disclosed in Japanese Patent Publication Laid-Open No. 112/79 (JP-A-54-112). The disadvantage of this conventional system, however, is that, as the correction factors are updated, the correction factor may be rewritten into an abnormal value by such adverse phenomenon as runaway of the digital computer, a drop in the battery output voltage at the time of start or noise. As a result, the controllability is deteriorated, thereby rendering the control faulty.